import java.util.Scanner;

/**
 * Created with IntelliJ IDEA.
 * Description: 第八题
 * User: 姚东名
 * Date: 2024-11-16
 * Time: 10:22
 */
public class Demo3 {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        String input = scanner.nextLine();

        // 用减号 "-" 把a和b分隔开
        String[] parts = input.split("-");

        // 将字符串转化为整数
        int a = Integer.parseInt(parts[0]);
        int b = Integer.parseInt(parts[1]);

        // 计算减法公式
        int result = a - b;

        System.out.println(result);
    }
}
